1. Field of the Invention
The present invention relates to a light emission device that is designed to control a temperature of a rear substrate on which electron emission regions are located. The present invention further relates to a display device using the light emission device as a light source.
2. Description of Related Art
Devices that can emit light to an external side can be referred to as light emission devices. One type of light emission devices includes a rear substrate on which electron emission regions and driving electrodes are formed, and a front substrate on which an anode electrode and a phosphor layer are formed. This light emission device emits visible light by exciting the phosphor layer using electrons emitted from the electron emission regions.
In more detail, the light emission device is operated by i) controlling an amount of electrons emitted from the electron emission regions by applying driving voltages (scan and data driving voltages) to the driving electrodes and ii) accelerating the electrons emitted from the electron emission regions toward the phosphor layer by applying a positive direct current voltage (anode voltage) of hundreds to thousands of volts to the anode electrode.
The light emission device may be used as a light source for emitting light to a passive type display panel of a display device.
In an initial driving state of the light emission device or when the light emission device is driven under a low temperature environment, electron emission cannot be sufficiently realized due to the rear substrate being in a low temperature state. That is, it takes a relatively long time to increase an emission amount of electrons to a proper level with a certain (or predetermined) driving voltage to thus stabilize the electron emission property.
Furthermore, when the light emission device is being driven, there may be a temperature difference between the front and rear substrates. This temperature difference may cause cracks to be generated on and/or in the substrates, thereby deteriorating lifespan and reliability of the light emission device. The temperature difference also adversely affects the spacers arranged between the front and rear substrates by varying a surface potential of the spacers, thereby deteriorating an electron beam path around the spacers.